Locking the stable door after the horse has bolted. The Peppergate in Chester produced a similar saying. It is noted in several histories of the city and I checked the references. The Peppergate gained notoriety when, in 1573, Ellen, the daughter of Mayor Aldersey eloped through it with her lover, leaving the City Assembly to order, on 15th January 1573 that the gate be shut! This gave rise to a Chester proverb about shutting the Peppergate after the daughter had gone (similar to shutting the stable door after the horse had bolted).Later, in April that year, perhaps after the Mayor had calmed down, thegate was shut at night and opened in the day.